SOLUTION: If the numerator of a fraction is increased by 3, the fraction becomes 3/4. If the denominator is decreased by 7, the fraction becomes 1. Find the original fraction.

Algebra ->  Test -> SOLUTION: If the numerator of a fraction is increased by 3, the fraction becomes 3/4. If the denominator is decreased by 7, the fraction becomes 1. Find the original fraction.       Log On


   

Question 1096840: If the numerator of a fraction is increased by 3, the fraction becomes 3/4. If the denominator is decreased by 7, the fraction becomes 1. Find the original fraction.
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
If the numerator of a fraction is increased by 3, the fraction becomes 3/4.
If the denominator is decreased by 7, the fraction becomes 1.
Find the original fraction
"
n%2Fd = original fraction
"If the numerator of a fraction is increased by 3, the fraction becomes 3/4."
%28%28n%2B3%29%29%2Fd = 3%2F4
Cross multiply
4(n+3) = 3d
4n + 12 = 3d
:
"If the denominator is decreased by 7, the fraction becomes 1."
n%2F%28%28d-7%29%29+=+1
Cross multiply
1n = d - 7
n = (d-7)
In the 1st equation replace n with d-7
4(d-7) + 12 = 3d
4d - 28 + 12 = 3d
4d - 3d - 16 = 0
d = 16 is the denominator
then
n = 16 - 7
n = 9
:
9%2F16 = the original equation